Complementing what "Freak100" said:
If you do ONLY bad things, you get "When you're evil". If you do ONLY good things, you get "Mrs. nice girl". If you do bad and good things (doesn't need to be the same amount of bad and good things), you get "Gray Fox". Thanks for the guide!
Freak100
Apparently, for Gray Fox you can also to do exactly the same amount of nice and bad things. Doing 1 more thing of either could give you the other medals, Im not sure aboutthat